Sciatica is the name given to a set of symptoms that include pain caused by the compression or irritation of the spinal nerves. The pain typically is felt in the back, down the legs and in the buttocks, and it might be accompanied by numbness, a feeling of "pins and needles" and difficultly in moving or controlling the affected limbs. There also might be significant muscle weakness. Sciatic nerve damage can result from a variety of causes but is rarely permanent.
The most common type of sciatic nerve damage is caused by a slipped disc, also referred to as a herniated disc. This occurs when the outer part of a disc cracks, allowing the inner gel to bulge and lose shape, which causes it to press again the sciatic nerve. This causes the symptoms of sciatica and usually lasts less than six months. Cases that last longer than this are referred to as persistent sciatica and might need more intense treatment.
Another cause of sciatic nerve damage is spinal stenosis. This is the name given to the narrowing of nerve passages in the spine, which usually occurs when bones, ligaments and discs move and squash the nerves into a much smaller area. This puts pressure on the sciatic nerve, causing sciatic nerve damage and therefore sciatica. Spinal stenosis usually occurs in late middle age and older, and it can be a short-lived or long-term condition. It can be treated with physiotherapy and pain medications, although the effectiveness of this varies.
The sciatic nerve also can be damaged because of spinal injury. The most common injuries resulting in serious sciatic nerve damage are motorcycle or car crashes involving enough force to create permanent, long-lasting damage to the nerve. Tumors or other growths can also cause sciatic nerve damage, depending on their size and location. In this case, the tumor might need to be removed or shrunken for symptoms to disappear, although medication is available to control the symptoms. Spinal infections can also cause sciatic nerve damage, although this is rare.